Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period
Abstract Declining Arctic sea ice is increasing polar bear land use. Polar bears on land are thought to minimize activity to conserve energy. Here, we measure the daily energy expenditure (DEE), diet, behavior, movement, and body composition changes of 20 different polar bears on land over 19–23 day...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2024-02-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-44682-1 |
| _version_ | 1797274085185552384 |
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| author | Anthony M. Pagano Karyn D. Rode Nicholas J. Lunn David McGeachy Stephen N. Atkinson Sean D. Farley Joy A. Erlenbach Charles T. Robbins |
| author_facet | Anthony M. Pagano Karyn D. Rode Nicholas J. Lunn David McGeachy Stephen N. Atkinson Sean D. Farley Joy A. Erlenbach Charles T. Robbins |
| author_sort | Anthony M. Pagano |
| collection | DOAJ |
| description | Abstract Declining Arctic sea ice is increasing polar bear land use. Polar bears on land are thought to minimize activity to conserve energy. Here, we measure the daily energy expenditure (DEE), diet, behavior, movement, and body composition changes of 20 different polar bears on land over 19–23 days from August to September (2019–2022) in Manitoba, Canada. Polar bears on land exhibited a 5.2-fold range in DEE and 19-fold range in activity, from hibernation-like DEEs to levels approaching active bears on the sea ice, including three individuals that made energetically demanding swims totaling 54–175 km. Bears consumed berries, vegetation, birds, bones, antlers, seal, and beluga. Beyond compensating for elevated DEE, there was little benefit from terrestrial foraging toward prolonging the predicted time to starvation, as 19 of 20 bears lost mass (0.4–1.7 kg•day−1). Although polar bears on land exhibit remarkable behavioral plasticity, our findings reinforce the risk of starvation, particularly in subadults, with forecasted increases in the onshore period. |
| first_indexed | 2024-03-07T14:53:19Z |
| format | Article |
| id | doaj.art-3ea54212e34d4c16b1874505240cd213 |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-07T14:53:19Z |
| publishDate | 2024-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-3ea54212e34d4c16b1874505240cd2132024-03-05T19:32:55ZengNature PortfolioNature Communications2041-17232024-02-0115111510.1038/s41467-023-44682-1Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free periodAnthony M. Pagano0Karyn D. Rode1Nicholas J. Lunn2David McGeachy3Stephen N. Atkinson4Sean D. Farley5Joy A. Erlenbach6Charles T. Robbins7U. S. Geological Survey, Alaska Science CenterU. S. Geological Survey, Alaska Science CenterWildlife Research Division, Science and Technology Branch, Environment and Climate Change CanadaWildlife Research Division, Science and Technology Branch, Environment and Climate Change Canada226104 Melrose RoadAlaska Department of Fish and GameSchool of Biological Sciences, Washington State UniversitySchool of Biological Sciences, Washington State UniversityAbstract Declining Arctic sea ice is increasing polar bear land use. Polar bears on land are thought to minimize activity to conserve energy. Here, we measure the daily energy expenditure (DEE), diet, behavior, movement, and body composition changes of 20 different polar bears on land over 19–23 days from August to September (2019–2022) in Manitoba, Canada. Polar bears on land exhibited a 5.2-fold range in DEE and 19-fold range in activity, from hibernation-like DEEs to levels approaching active bears on the sea ice, including three individuals that made energetically demanding swims totaling 54–175 km. Bears consumed berries, vegetation, birds, bones, antlers, seal, and beluga. Beyond compensating for elevated DEE, there was little benefit from terrestrial foraging toward prolonging the predicted time to starvation, as 19 of 20 bears lost mass (0.4–1.7 kg•day−1). Although polar bears on land exhibit remarkable behavioral plasticity, our findings reinforce the risk of starvation, particularly in subadults, with forecasted increases in the onshore period.https://doi.org/10.1038/s41467-023-44682-1 |
| spellingShingle | Anthony M. Pagano Karyn D. Rode Nicholas J. Lunn David McGeachy Stephen N. Atkinson Sean D. Farley Joy A. Erlenbach Charles T. Robbins Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period Nature Communications |
| title | Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period |
| title_full | Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period |
| title_fullStr | Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period |
| title_full_unstemmed | Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period |
| title_short | Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period |
| title_sort | polar bear energetic and behavioral strategies on land with implications for surviving the ice free period |
| url | https://doi.org/10.1038/s41467-023-44682-1 |
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